**2. Pesticides**

Agricultural output has been increased dramatically in the early 20th century, especially in the United States, to keep up with the rapidly growing human population. During the last century, the world's population has tripled from 1.5 billion in 1900 to 6.1 billion in 2000. The world's population has grown by one billion people in the past decade, and the UN predicts it could reach 9.4 to 10 billion by 2050 if current growth rates continue [22]. A lateral increase in food production was needed during the 20th century to keep up with the increase in the world population. This was accomplished via the use of fertilizers and other agricultural inputs throughout the twentieth century. Bio-fertilizers (such as guano) were first used in the late 1800s; inorganic phosphate fertilizers (such as urea) were first used in the early 1900s and have steadily gained in favor ever since [23]. Phosphates helps to increase the crop diversity and yields and aided in the unprecedented "green revolution" for agricultural productivity. This caused a tenfold increase in grain

production per unit surface area of agricultural land, leading to a global food surplus [24]. An increasing global population and increased phosphate production were shown to be positively linked throughout the 20th century, with an R2 of 0.97 for the period 1900–1988 [25].

Synthetic crop preservation agents were introduced to the market in the 1940s, which increased food output. It grew from 0.2 million tons in 1950 to over 5 million tons in 2000, up from 0.2 million tons the year before. Between 1950 and 2000, pesticide production grew by about 11%, from 0.2 million tons to over 5 million tons. Crop preservation chemicals, sometimes known as pesticides, are composed of various composites, including growth regulators, neonicotinoids, organochlorines, pyrethroids, organophosphates, carbamates, and more recently, biopesticides. This wide spectrum of chemicals and insecticides has been developed throughout history to protect crops from pests and diseases. All sorts of pesticide sales grew; however, herbicides were the group that extended the most, accompanied by fungicides and insecticides. Pesticide application has suffered owing to lack of global uniformity, high cost of chemicals, human resources, and the vast diversity of pests present in each climatic or geographical area. Using FAO data, it was found that the mean pesticide application rates per hectare of arable land ranged from 6.5 to 60 kg/ ha, with the greatest mean values occurring in Asia and a few South American nations. Unlike Western Europe and North America, Asia has not witnessed a rise in the usage of herbicides in both urban and agricultural areas. Compared to the widespread use of insecticides, herbicide usage in Asia has remained relatively low in recent years, according to World Bank and International Food Policy Research Institute data [26].

Throughout the twentieth century, ancient synthetic pesticides intended for agricultural pest control, such as DDT, were often used to treat human parasites and animal ticks. So, for example, DDT was designed to be used in agricultural pest control. Despite of being prohibited, it is nevertheless extensively used as a food prophylactic for various fish in South Asia, and to control home pests and malaria vectors globally, albeit seldom illegally [27]. Pesticides have been administered in agricultural settings for decades, employing techniques ranging from truck and aircraft spraying to old-fashioned field worker spraying. Studies on the effects and toxicity of manufactured chemicals on human health and well-being have shown that individuals report euphoria after pesticide application. This research included peasants, farmworkers, and their families following pesticide treatments. They previously discovered that unintentional poisoning affects about 355,000 individuals annually and is linked to high susceptibility and poor chemical management. They also discovered that increased sensitivity and poor management of hazardous substances are closely linked to such toxicities [28]. The research was conducted to assess the number of pesticides in the environment that killed various animals. Among the animals that resided there were fish, birds, bees, amphibians, and tiny mammals. It was also noted how much they were killed and how they were slaughtered [29].

Following the introduction of synthetic chemicals into the environment, it was only a short amount of time before it was thought that crop protection pesticides were causing disease both locally and internationally [26]. Many believe that sprayed on-crop DDT is deported into water bodies, quickly converted into DDE, and bio-accumulated in aquatic food systems before being reintroduced into the environment and ultimately reaching people. To manufacture endosulfan at this time, a rigorous and scientific decision-making procedure is undertaken. Additionally, this strategy includes scientific research to enhance food production, food safety, and environmental security in addition to the other objectives listed above [26].

Common use of synthetic pesticides inhibits the development of plant pathogen strains resistant to these chemicals, causing the reemergence of illnesses in the

*Nano-Biopesticides as an Emerging Technology for Pest Management DOI: http://dx.doi.org/10.5772/intechopen.101285*

environment. Pesticides are being used more often by farmers, which is good [30]. Synthetic pesticides include active ingredients that are absorbed and retained by plants after application. People suffer chronic health issues due to the high concentration of harmful chemical deposits in these crops cultivated for human use [31]. Synthetic pesticides include active ingredients that are absorbed and retained by plants after application. People are suffering from chronic health issues due to the high concentration of harmful chemical deposits in these crops cultivated for human use [32].
